Code No. P0703: Malfunction of Stop Lamp Switch
DIAGNOSTIC FUNCTION
JUDGEMENT CRITERIA
PROBABLE CAUSES
- Malfunction of the CAN bus
- Malfunction of the stop lamp switch
- Damaged wiring harness and connectors
- Malfunction of A/T-ECU
- Malfunction of ETACS-ECU
DIAGNOSTIC PROCEDURE |
STEP 1. M.U.T.-III CAN bus diagnostics |
| Use M.U.T.-III to perform the CAN bus diagnosis. |
Q.
Is the check result normal?
|
 Go to Step 2. |
|
 Repair the CAN bus lines (Refer to GROUP 54C - Troubleshooting, Diagnosis
Code Chart  ). |
|
STEP 2. M.U.T.-III data list |
| Item 60: Brake switch |
| OK: The service data changes in response to the brake operation. |
Q.
Is the check result normal?
|
| Intermittent malfunction |
|
| Go to Step 3. |
|
STEP 3. Stop Lamp Switch Check |
| Refer to GROUP 35A - Brake Pedal and Stop Lamp Switch Continuity Check (Refer
to ). |
Q.
Is the check result normal?
|
| Go to Step 4. |
|
| Replace the stop lamp switch. |
|
STEP 4. Check for open circuit in the power supply line between the stop lamp switch connector and the ETACS-ECU connector. |
Q.
Is the check result normal?
|
| Go to Step 5. |
|
| Repair the connector(s) or wiring harness. |
|
STEP 5. Check for open circuit or short to earth in signal line between the ETACS-ECU connector and the stop lamp switch connector |
Q.
Is the check result normal?
|
| Go to Step 6. |
|
| Repair the connector(s) or wiring harness. |
|
STEP 6. Symptom recheck after erasing diagnosis code |
Q.
Is the check result normal?
|
| Intermittent malfunction |
|
| Replace the ETACS-ECU, and then go to Step 7. |
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STEP 7. Symptom recheck after erasing diagnosis code |
Q.
Is the check result normal?
|
| Intermittent malfunction |
|
| Replace A/T-ECU. |
|